1. Field of the Invention
The present invention relates to a tool arrangement for a rotary machining tool, and to a machining center with such a tool arrangement.
2. Description of Related Art
Tool arrangements for rotary machining tools, such as generating and profile grinding machines, for fixing a tool, in particular a grinding disk, are known from the prior art. In these generating and profile grinding machines one difficulty consists in that due to the occurring machining forces deformations are obtained at the tool holder, which are transmitted to other machine parts and to the housing of the machines.
Conventionally, the tool is clamped onto a mandrel which in turn is put onto the tool spindle via a steep cone chuck, braced and thereby driven. There occur imbalances and with long superstructures also wobbling effects. At the same time, the rigidity decreases with the length of the arrangement.
To compensate the undesired effects explained above, a counter bearing is required with increasing width of the tools. With narrower tools, a counter bearing can be omitted, as in general the tool mandrel and the spindle shaft are designed in one piece and the tool is arranged close to the spindle bearing.
The spindle generally is driven by an integrated motor or by a belt. The bearings, for example high-precision ball bearings, must be designed such that a sufficient rigidity of the connection, in particular also at high speeds, can be made possible. The bearings required for this purpose mostly are designed as anti-friction bearings and are available in different designs, such as e.g. single-row universal bearings. To increase the rigidities, the bearings are arranged or paired and biased in different ways, for example in an O-arrangement, an X-arrangement, a tandem -O- or a tandem -X- arrangement. In a spindle set-up, the arrangement of the bearings varies very much and depends on the respective conditions of use.
Mounting the tool on the spindle generally is effected by means of a tool mandrel. The tool mandrel frequently is braced with the spindle by means of a hollow shank cone and a clamping cartridge. In general, the hollow shank cone is seated in the tool holder, and the hollow shank cone receptacle including the clamping cartridge is seated in the spindle.